Mikrolitográfia

Mikrolitográfia, often simply referred to as lithography, is a process used in microfabrication to pattern thin films on a substrate. It is a key technology in the manufacturing of integrated circuits, microelectromechanical systems (MEMS), and other micro-devices. The fundamental principle involves selectively transferring a geometric pattern from a mask to a light-sensitive chemical called a photoresist on the substrate surface.

The process typically begins with a substrate, such as a silicon wafer, coated with a layer of photoresist. A photomask, which contains the desired pattern, is then positioned above the wafer. Next, a light source, usually ultraviolet (UV) light, is directed through the photomask. The light exposes specific areas of the photoresist, causing a chemical change. Following exposure, the wafer is developed, which removes either the exposed (positive resist) or unexposed (negative resist) portions of the photoresist, leaving the patterned resist layer behind.

This patterned photoresist then acts as a stencil for subsequent processing steps. For instance, it can be used to protect certain areas of the underlying material during etching, where unwanted material is removed by chemical or physical means. Alternatively, the patterned resist can be used to selectively deposit materials in specific locations. After the etching or deposition step, the remaining photoresist is stripped away, revealing the patterned underlying layer. This entire sequence can be repeated multiple times to build up complex three-dimensional structures with intricate features on a microscopic scale. The resolution of mikrolitográfia is determined by the wavelength of light used and the optical system's ability to focus that light.